Method and system of determining whether a mobile station is located inside a coverage area of a narrowband repeater and using the determination in a handover procedure

BACKGROUND

p-0002In a typical cellular wireless network, an area is divided geographically into a number of coverage areas, such as cells and sectors, each defined by a radio frequency (RF) radiation pattern from a respective base station). Within each coverage area, the base station's RF radiation pattern provides one or more wireless links, each on a corresponding carrier, over which mobile stations may communicate with the cellular wireless network. In turn, the cellular wireless network may provide connectivity with one or more other networks, such as the public switched telephone network (PSTN) or the Internet.

p-0003The cellular wireless network described above may additionally include one or more repeaters, each of which functions to repeat signals between a base station and a mobile station. Typically, a repeater is employed to extend the range of a coverage area and/or fill a hole in a coverage area. In operation, a repeater may receive signals from a base station, amplify the signals, and then transmit the amplified signals into the repeater's coverage area for receipt by a mobile station. Correspondingly, the repeater may receive signals from a mobile station located inside the repeater's coverage area, amplify the signals, and then transmit the amplified signals to the base station. The repeater may perform other functions as well.

p-0004One common type of repeater is a narrowband repeater, which can only repeat signals on one carrier—and thus one wireless link—between a base station and a mobile station. In this respect, when a narrowband router is employed in a coverage area having multiple wireless links, problems may arise. One problem with employing a narrowband repeater in a coverage area having multiple wireless links is that a base station may not be able to readily determine whether a given mobile station is located inside a coverage area of a repeater amplifying one of the wireless links. In turn, the base station may not be able to account for the given mobile station's presence inside (or outside) the narrowband repeater's coverage area during a handover procedure (e.g., an active session load balancing handover procedure), which may result in a dropped call. Accordingly, an improved method for determining whether a mobile station is located inside a narrowband repeater's coverage area and using the determination in a handover procedure is desired.

OVERVIEW

p-0005Disclosed herein are methods of determining whether a mobile station is located inside a coverage area of a repeater and using the determination in a handover procedure.

p-0006A method of determining whether a mobile station is located inside a coverage area of a repeater may include an access network (a) communicating with a mobile station over a first wireless link, (b) receiving from the mobile station an indication of channel quality (e.g., carrier-to-interference noise ratio and/or received signal strength indication) for each of the first wireless link and a second wireless link detected by the mobile station, (c) determining that the first wireless link and the second wireless link serve a same coverage area of the access network, and (d) after determining that the first wireless link and the second wireless link serve the same coverage area of the access network, using the received indications of channel quality for the first wireless link and the second wireless link to determine whether the mobile station is located inside a coverage area of a repeater.

p-0007If the access network determines that the mobile station is located inside a coverage area of a repeater, the method may also include additional features. For example, the method may additionally include a feature of confirming that one of the first wireless link and the second wireless link is being repeated by a repeater. As another example, the method may additionally include a feature of determining which of the first wireless link and the second wireless link is being repeated by the repeater, such as by determining which of the first wireless link and the second wireless link has a greater indication of channel quality and/or determining which of the first wireless link and the second wireless link is being repeated by the repeater based on data indicating which wireless links of the access network are being repeated by a repeater.

p-0008The feature of using the received indications of channel quality for the first wireless link and the second wireless link to determine whether the mobile station is located inside a coverage area of a repeater may take various forms. In one example, this feature may include (1) calculating a difference between the received indications of channel quality for the first wireless link and the second wireless link, (2) comparing the calculated difference to a first threshold, (3) if the calculated difference is greater than the first threshold, determining that the mobile station is located inside a coverage area of a repeater; otherwise, and (4) if the calculated difference is less than or equal to the first threshold, determining that the mobile station is located outside a coverage area of a repeater. Additionally, this feature may include determining that one of the received channel indications is greater than a second threshold before calculating a difference between the received indications of channel quality for the first wireless link and the second wireless link.

p-0009A method of handing over a communication with a mobile station moving into a coverage area of a repeater may include an access network (a) engaging in a communication with a first mobile station over a first wireless link, (b) receiving from the first mobile station a request to initiate a handover of the communication from the first wireless link to a new wireless link, wherein the request includes an indication of channel quality for each of the first wireless link and a second wireless link detected by the first mobile station, (c) in response to receiving the request, determining that the first mobile station is moving into a coverage area of a repeater that repeats the second wireless link, and (d) in response to determining that the first mobile station is moving into a coverage area of a repeater that repeats the second wireless link, initiating a handover of the communication with the first mobile station from the first wireless link to the second wireless link. In this respect, the feature of determining that the mobile station is moving into a coverage area of a repeater that repeats the second wireless link may include features similar to those described above for determining whether a mobile station is located inside a coverage area of a repeater.

p-0010The feature of initiating the handover of the communication with the first mobile station from the first wireless link to the second wireless link may also take forms. In one example, this feature may include suspending application of a load threshold that would have otherwise been applied to the second wireless link. In this respect, the feature of suspending application of a load threshold that would have otherwise been applied to the second wireless link may include disregarding a predefined load threshold for the second wireless link.

p-0011The method of handing over the communication may also include additional features. For example, the method may additionally include the access network (e) after initiating the handover of the communication with the first mobile station from the first wireless link to the second wireless link, determining that the second wireless link is highly loaded, (f) in response to determining that the second wireless link is highly loaded, deciding to initiate a handover of a communication from the second wireless link to another wireless link, (g) identifying for the handover a second mobile station that is (1) engaging in a communication with the access network over the second wireless link and (2) located outside the coverage area of the repeater, and (h) handing over the communication with the second mobile station from the second wireless link to another wireless link. In this respect, the feature of identifying for the handover a second mobile station that is located outside the coverage area of the repeater may include features similar to those described above for determining whether a mobile station is located inside a coverage area of a repeater.

p-0012Also disclosed herein is a base station that includes (a) an antenna structure for communicating with one or more mobile stations over respective wireless links, (b) a communication interface for communicating with a network entity, (c) a processor, (d) data storage, and (e) program instructions stored in the data storage and executable by the processor for carrying out functions described herein.

p-0013These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0014<figref idrefs="DRAWINGS">FIG. 1</figref> is a simplified block diagram of a communication system in which an exemplary method can be implemented;

p-0015<figref idrefs="DRAWINGS">FIG. 2</figref> is a flow chart depicting an exemplary method of determining whether a mobile station is located inside a coverage area of a repeater;

p-0016<figref idrefs="DRAWINGS">FIG. 3</figref> is an illustration of channel quality as a mobile station moves into a coverage area of a repeater in the communication system depicted in <figref idrefs="DRAWINGS">FIG. 1</figref>;

p-0017<figref idrefs="DRAWINGS">FIG. 4</figref> is a flow chart depicting an exemplary method of handing over a communication with a mobile station moving into a coverage area of a repeater; and

p-0018<figref idrefs="DRAWINGS">FIG. 5</figref> is a simplified block diagram showing functional components of an exemplary base station capable of carrying out the exemplary methods of <figref idrefs="DRAWINGS">FIGS. 2-3</figref>.

DETAILED DESCRIPTION

p-0019Referring to the drawings, <figref idrefs="DRAWINGS">FIG. 1</figref> is a simplified block diagram of a communications system in which an exemplary method can be implemented. As shown, the system includes an access network <b>12</b>, which may function to provide connectivity between one or more mobile stations (e.g., cell phones, PDAs, netbooks, tablets, and/or other wirelessly-equipped devices), such as a first mobile station <b>14</b><i>a </i>and a second mobile station <b>14</b><i>b</i>, and one or more packet-switched networks (e.g., the global Internet), such as a packet-switched network <b>18</b>.

p-0020It should be understood, however, that this and other arrangements described herein are set forth for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, functions, orders of functions, etc.) can be used instead, some elements may be added, and some elements may be omitted altogether. Further, as in most telecommunications applications, those skilled in the art will appreciate that many of the elements described herein are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, and in any suitable combination and location. Still further, various functions described herein as being performed by one or more entities may be carried out by hardware, firmware and/or software logic. For instance, various functions may be carried out by a processor executing a set of machine language instructions stored in memory.

p-0021As shown, access network <b>12</b> may include one or more base stations, such as a base station <b>20</b>. (Although <figref idrefs="DRAWINGS">FIG. 1</figref> depicts access network <b>12</b> as including a single base station, it should be understood that access network <b>12</b> may include more than one base station). Base station <b>20</b> may be any entity that facilitates communication between one or more mobile stations and access network <b>12</b>. In this respect, base station <b>20</b> may radiate to define one or more wireless coverage areas (e.g., cells or cell sectors). Within each coverage area, base station <b>20</b> may provide one or more wireless links, each on a corresponding carrier, over which mobile stations located in the coverage area may communicate with base station <b>20</b>. (As used herein, the term carrier may encompass a single carrier frequency or a group of carrier frequencies).

p-0022The wireless links of base station <b>20</b> will preferably carry communications between access network <b>12</b> and mobile station according to a Worldwide Interoperability for Microwave Access (WiMAX) protocol (e.g., IEEE 802.16). Alternatively, the wireless links may carry communications according to any other protocol now known or later developed, including CDMA (e.g., 1xRTT or 1xEV-DO (IS-856)), iDEN, TDMA, AMPS, GSM, GPRS, UMTS, EDGE, LTE, microwave, satellite, MMDS, Wi-Fi (e.g., IEEE 802.11), Bluetooth, and infrared. Depending on the protocol employed, the wireless links will also preferably be divided into a plurality of channels for carrying communications between mobile station and access network <b>12</b>, such as downlink channels for carrying communications from access network <b>12</b> to mobile stations and uplink channels for carrying communications from mobile stations to access network <b>12</b>.

p-0023Due to hardware and protocol constraints, each wireless link can only provide a finite number of channels, and thus can only support a finite number of simultaneous communications between access network <b>12</b> and mobile stations. In this respect, to increase a number of simultaneous communications that can occur between access network <b>12</b> and mobile stations in a particular coverage area, a base station may be configured to provide multiple wireless links in that coverage area. Such a configuration may be desirable in heavily-populated coverage areas (e.g., large cities).

p-0024For purposes of illustration, <figref idrefs="DRAWINGS">FIG. 1</figref> depicts base station <b>20</b> being configured to provide two wireless links WL<b>1</b> and WL<b>4</b> in a first sector S<b>1</b>, two wireless links WL<b>2</b> and WL<b>5</b> in a second sector S<b>2</b>, and one wireless link WL<b>3</b> in a third sector S<b>3</b>, with each wireless link having a 10 MHz frequency band. It should be understood, however, that the depicted configuration of sectors and wireless links is for purposes of illustration only, and that many other examples are possible as well.

p-0025Base station <b>20</b> of access network <b>12</b> may then couple to a core network <b>22</b>, which provides connectivity with various other network entities. For example, core network <b>22</b> may provide connectivity with an access service node gateway (ASN-GW) <b>24</b> that functions to communicate with base station <b>20</b> and control aspects of base station <b>20</b> as well as aspects of the wireless communication with the mobile station. (Although <figref idrefs="DRAWINGS">FIG. 1</figref> depicts access network <b>12</b> as including one ASN-GW connected to one base station, it should be understood that access network <b>12</b> may include more than one ASN-GW and that each ASN-GW may couple to multiple base stations). ASN-GW <b>24</b> may also provide connectivity with packet-switched network <b>18</b>. As another example, core network <b>22</b> may provide connectivity with an element management system (EMS) <b>26</b> that functions to maintain data about the access network <b>12</b>, such as data defining the configuration of the access network <b>12</b>.

p-0026As shown, access network <b>12</b> may additionally include one or more repeaters that each function to repeat signals on a corresponding wireless link, such as a narrowband repeater <b>28</b> that repeats signals on wireless link WL<b>4</b> (and the corresponding 10 MHz carrier) in sector S<b>1</b>. Narrowband repeater <b>28</b> may radiate to define a coverage area in which narrowband repeater <b>28</b> provides a repeated version of wireless link WL<b>4</b>. Preferably, the repeater's coverage area will fill a hole in sector S<b>1</b> in which wireless links WL<b>1</b> and WL<b>4</b> have insufficient channel quality (e.g., carrier-to-interference noise ratio (CINR) and/or received signal strength indication (RSSI)) to support a communication with a mobile station <b>14</b>. As such, in the narrowband repeater's coverage area, only the repeated version of wireless link WL<b>4</b> may have sufficient channel quality to support a communication with a mobile station.

p-0027In operation, narrowband repeater <b>28</b> may receive signals from base station <b>20</b> over wireless link WL<b>4</b>, amplify the signals, and then transmit the amplified signals into the repeater's coverage area over the repeated version of wireless link WL<b>4</b> for receipt by a mobile station. Correspondingly, narrowband repeater <b>28</b> may receive signals from a mobile station located inside the repeater's coverage area over the repeated version of wireless link WL<b>4</b>, amplify the signals, and then transmit the amplified signals to base station <b>20</b> over wireless link WL<b>4</b>. The narrowband repeater <b>28</b> may perform other functions as well.

p-0028Most repeaters available today perform only limited processing on the signals they repeat, and do not otherwise engage in communication with other entities. As such, when access network <b>12</b> is engaging in a communication with a mobile station, access network <b>12</b> may not be able to readily determine whether that mobile station is located inside a coverage area of a repeater, and in turn, whether the communication is passing through the repeater. For example, if access network <b>12</b> is engaging in a communication with mobile station <b>14</b><i>a </i>over wireless link WL<b>4</b>, access network <b>12</b> may not be able to readily determine whether mobile station <b>14</b><i>a </i>is located in the coverage area of narrowband repeater <b>28</b>, and in turn, whether the communication is passing through narrowband repeater <b>28</b>.

p-0029Accordingly, disclosed herein is an exemplary method of determining whether a mobile station is located inside a coverage area of a repeater. The exemplary method is based on the principle that, absent a repeater, wireless links provided by the same base station in the same wireless coverage area (e.g., wireless links WL<b>1</b> and WL<b>4</b> in sector S<b>1</b>) typically have similar channel quality (e.g., CINR and/or RSSI). As such, if a mobile station located in a wireless coverage area with multiple wireless links detects different levels of channel quality on those wireless links, the mobile station is likely located inside a coverage area of a repeater for one of those wireless links.

p-0030<figref idrefs="DRAWINGS">FIG. 2</figref> is a flow chart depicting an exemplary method of determining whether a mobile station (e.g., mobile station <b>14</b><i>a</i>) is located inside a coverage area of a repeater. For purposes of illustration, the following description will assume that access network <b>12</b> is initially communicating with mobile station <b>14</b><i>a </i>over wireless link WL<b>1</b> in sector S<b>1</b>, narrowband repeater <b>28</b> repeats signals on wireless link WL<b>4</b> in sector S<b>1</b>, and base station <b>20</b> carries out the exemplary method.

p-0031The exemplary method may begin at step <b>32</b> when base station <b>20</b> receives from mobile station <b>14</b><i>a </i>an indication of a channel quality (e.g., CINR and/or RSSI) for each of wireless link WL<b>1</b> and at least one other wireless link detected by mobile station <b>14</b><i>a </i>(e.g., wireless link WL<b>4</b>). Preferably, along with the indication of channel quality for each of wireless link WL<b>1</b> and the detected wireless link, base station <b>20</b> will also receive an identifier of each of wireless link WL<b>1</b> and the detected wireless link. Base station <b>20</b> may receive the indications of channel quality and the identifiers from mobile station <b>14</b><i>a </i>in various manners. In one example, base station <b>20</b> may receive the indications of channel quality and the identifiers in a MOV_SCN-REP message, which mobile station <b>14</b><i>a </i>may send to report the result of a wireless-link scan. As another example, the base station <b>20</b> may receive the indications of channel quality and the identifiers in a MOB_MSHO-REQ message, which mobile station <b>14</b><i>a </i>may send to request a handover. Other examples are possible as well.

p-0032At step <b>34</b>, after receiving the indication of channel quality for each of wireless link WL<b>1</b> and the detected wireless link, base station <b>20</b> may determine whether wireless link WL<b>1</b> and the detected wireless link serve the same coverage area. Base station <b>20</b> may make this determination using various techniques. In one aspect, base station <b>20</b> may determine whether wireless link WL<b>1</b> and the detected wireless link serve the same coverage area based on data defining the base station's wireless links, which may be maintained at base station <b>20</b> and/or another entity accessible to base station <b>20</b> (e.g., EMS <b>26</b>). Preferably, the data defining the base station's wireless links will include an identifier of each wireless link and an identifier of each wireless link's coverage area. Additionally, the data defining the base station's wireless links may include an association between identifiers of wireless links that serve the same coverage area. Using this data, in one example, base station <b>20</b> may identify the first wireless link's coverage area and the detected wireless link's coverage area and then compare the identified coverage areas to determine whether they are the same coverage area. In another example, base station <b>20</b> may determine whether the identifiers of wireless link WL<b>1</b> and the detected wireless link are associated. Other examples are possible as well.

p-0033If base station <b>20</b> determines that wireless link WL<b>1</b> and the detected wireless link serve the same coverage area (e.g., the detected wireless link is wireless link WL<b>4</b>), base station <b>20</b> may then proceed to step <b>36</b>. At step <b>36</b>, base station <b>20</b> may then use the received indications of channel quality (e.g., CINR and/or RSSI) for wireless link WL<b>1</b> and wireless link WL<b>4</b> to determine whether mobile station <b>14</b><i>a </i>is located inside a coverage area of a repeater. Preferably, base station <b>20</b> will determine whether mobile station <b>14</b><i>a </i>is located inside a coverage area of a repeater by comparing the received indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b>. Base station <b>20</b> may perform this comparison in various manners.

p-0034In one aspect, base station <b>20</b> may calculate a difference between the received indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b> and then compare the difference to a first threshold. In this respect, the first threshold may take various forms depending on a modulation scheme employed in the narrowband repeater's coverage area, among other factors. For example, the first threshold may be 6 dB for QPSK, 12 dB for 16QAM, or 20 dB for 64QAM. Many other examples are possible as well. If the calculated difference is greater than a first threshold (e.g. indicating that the wireless links have different channel conditions), base station <b>20</b> may determine that mobile station <b>14</b><i>a </i>is located inside the coverage area of a repeater. Alternatively, if the calculated difference is less than or equal to the first threshold (e.g. indicating that the wireless links have similar channel conditions), base station <b>20</b> may determine that mobile station <b>14</b><i>a </i>is located outside the coverage area of a repeater.

p-0035In another aspect, before calculating a difference between the received indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b> and comparing the difference to a first threshold, base station <b>20</b> may first compare the received indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b> to a second threshold, to determine that one of the received indications of channel quality exceeds the second threshold.

p-0036At step <b>38</b>, if base station <b>20</b> determines that mobile station <b>14</b><i>a </i>is located inside the coverage area of a repeater, base station <b>20</b> may also determine which of wireless link WL<b>1</b> and wireless link WL<b>4</b> is being repeated by the repeater. Base station <b>20</b> may make this determination using various techniques.

p-0037In one aspect, base station <b>20</b> may determine which of wireless link WL<b>1</b> and wireless link WL<b>4</b> is being repeated by narrowband repeater <b>28</b> based on the received indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b>. In this respect, base station <b>20</b> may determine that the wireless link with the greater indication of channel quality is the wireless link being repeated by a repeater (e.g., wireless link WL<b>4</b> in <figref idrefs="DRAWINGS">FIG. 1</figref>).

p-0038In another aspect, base station <b>20</b> may determine which of wireless link WL<b>1</b> and wireless link WL<b>4</b> is being repeated by narrowband repeater <b>28</b> based on the data defining the base station's wireless links, which may additionally include data indicating which wireless links are repeated by a repeater. In this respect, the base station <b>20</b> may look up wireless link WL<b>1</b> and wireless link WL<b>4</b> in the data defining the base station's wireless links (e.g., which is stored at base station <b>20</b> and/or EMS <b>26</b>), to determine which wireless link is being repeated by narrowband repeater <b>28</b> (e.g., wireless link WL<b>4</b> in <figref idrefs="DRAWINGS">FIG. 1</figref>). Base station <b>20</b> may also use the predefined data to confirm that one of wireless link WL<b>1</b> and wireless link WL<b>4</b> is being repeated by narrowband repeater <b>28</b>.

p-0039Accordingly, the exemplary method may provide access network <b>12</b> with an improved technique for determining whether a mobile station is located inside the coverage area of a repeater. Advantageously, the disclosed method of determining whether a mobile station is located inside a coverage area of a repeater may also be incorporated into an improved handover procedure that avoids interruption of communication (e.g., a dropped call due to application of a load threshold) with a mobile station moving into a coverage area of repeater and requesting a handover to the repeated wireless link.

p-0040In a typical handover procedure, base station <b>20</b> may receive from a mobile station (e.g., mobile station <b>14</b><i>a</i>) a request for a handover from wireless link WL<b>1</b> to a new wireless link. This handover request may identify one or more other wireless links detected by mobile station <b>14</b><i>a</i>. In response to receiving the handover request, base station <b>20</b> may whether each detected wireless link has sufficient channel parameters (e.g., capacity, quality of service (QoS), etc.) for the communication. If a detected wireless link has channel parameters with sufficient values, base station <b>20</b> may determine that the detected wireless link is suitable for the handover, and may ultimately hand over the communication from the first wireless link to the detected wireless link. Alternatively, if a detected wireless link has one or more channel parameters with insufficient values, base station <b>20</b> may determine that the detected wireless link is not suitable for the handover, and may ultimately refuse to hand over the communication from the first wireless link to the detected wireless link (and may instead hand over the communication to another wireless link).

p-0041While this handover procedure generally works well to facilitate seamless communication with the mobile station <b>14</b><i>a </i>as it moves through coverage areas of access network <b>12</b>, it may result in an interruption of communication when the mobile station <b>14</b><i>a </i>is communicating over wireless link WL<b>1</b> as it moves into the coverage area of narrowband repeater <b>28</b>—and thus the hole in sector S<b>1</b>. <figref idrefs="DRAWINGS">FIG. 3</figref> depicts such a scenario. As shown, as mobile station <b>14</b><i>a </i>moves into the coverage area of narrowband repeater <b>28</b>, it will detect a degrade in the channel quality of wireless link WL<b>1</b>. In turn, mobile station <b>14</b><i>a </i>may responsively request a handover of the communication from wireless link WL<b>1</b> to a new wireless link. This handover request will likely identify only wireless link WL<b>4</b> as a detected wireless link, be cause because mobile station <b>14</b><i>a </i>is located within first sector S<b>1</b> and the repeated wireless link WL<b>4</b> will be the only link with sufficient channel quality. If wireless link WL<b>4</b> does not have sufficient channel parameters (e.g., capacity and/or QoS) for the communication, however, base station <b>20</b> employing a typical handover procedure may refuse to hand over the communication to wireless link WL<b>4</b>. As mobile station <b>14</b><i>a </i>continues to move into the coverage area of narrowband repeater <b>28</b>—and the hole in sector S<b>1</b>—channel quality on the wireless link WL<b>1</b> may then become insufficient to support the communication, thus resulting in interruption (e.g., call drop and session disconnection).

p-0042Accordingly, disclosed herein is an exemplary handover procedure that may avoid this interruption in a coverage area with multiple wireless links, one of which is being repeated by a repeater. In such a configuration, the repeated wireless link may be supporting a number of communications with a base station, some of which need to pass through the repeater and others of which can occur directly with the base station. According to the exemplary handover procedure, the base station may use the techniques described above to identify which mobile stations are moving into a coverage area of the repeater, and thus which communications likely need to pass through the repeater. In turn, the base station may responsively handover communications that need to pass through the repeater from an unrepeated wireless link to the repeated wireless link, to avoid interruption of those communications. Similarly, if there is a high load on the repeated wireless link, the base station may use the techniques described above to identify which mobile stations are located outside a coverage area of the repeater, and thus which communications likely are occurring directly with the base station. In turn, the base station may handover communications occurring directly with the base station from the repeated wireless link to the unrepeated wireless link, to reduce the load on the repeated link.

p-0043<figref idrefs="DRAWINGS">FIG. 4</figref> is a flow chart depicting an exemplary method of handing over a communication with a mobile station (e.g., mobile station <b>14</b><i>a</i>) moving into a coverage area of a repeater. For purposes of illustration, the following description will assume that access network <b>12</b> is initially communicating with mobile station <b>14</b><i>a </i>over wireless link WL<b>1</b> in sector S<b>1</b>, mobile station <b>14</b><i>a </i>is moving into the coverage area of narrowband repeater <b>28</b> that repeats wireless link WL<b>4</b> in sector S<b>1</b>, and base station <b>20</b> carries out the exemplary method.

p-0044The exemplary method may begin at step <b>42</b> when base station <b>20</b> receives from mobile station <b>14</b><i>a </i>a request to initiate a handover of the communication from wireless link WL<b>1</b> to a new wireless link. The mobile station <b>12</b> may send this request in response to various triggers, such as detecting a decrease in the first wireless link's channel quality and/or scanning a neighbor wireless link with appreciably better channel conditions for instance. The mobile station's request will preferably include an identifier and an indication of channel quality (e.g., CINR and/or RSSI) for each of wireless link WL<b>1</b> and at least one other wireless link detected by mobile station <b>14</b><i>a</i>. In this respect, because mobile station <b>14</b><i>a </i>is moving into the coverage area of narrowband repeater <b>28</b> that repeats wireless link WL<b>4</b>, the mobile station's request will preferably include an identifier and an indication of channel quality for wireless link WL<b>4</b> as a detected wireless link.

p-0045At step <b>44</b>, base station <b>20</b> may determine that mobile station <b>14</b><i>a </i>is moving into the coverage area of narrowband repeater <b>28</b> that repeats wireless link WL<b>4</b>, preferably using techniques described above with reference to <figref idrefs="DRAWINGS">FIG. 2</figref>. For example, base station <b>20</b> may (a) determine that wireless link WL<b>1</b> and wireless link WL<b>4</b> serve the same coverage area, (b) use indications of channel quality for wireless link WL<b>1</b> and wireless link WL<b>4</b> that base station <b>20</b> received from mobile station <b>14</b><i>a </i>(e.g., in the handover request and/or a scan report) to determine that mobile station <b>14</b><i>a </i>is moving into the coverage area of a repeater, and then (c) determine that wireless link WL<b>4</b> is being repeated by the repeater.

p-0046At step <b>46</b>, in response to determining that mobile station <b>14</b><i>a </i>is moving into the coverage area of a repeater that repeats wireless link WL<b>4</b> (and thus that the communication likely needs to pass through the repeater), base station <b>20</b> may initiate a handover of the communication with mobile station from the wireless link WL<b>1</b> to wireless link WL<b>4</b>. In doing so, base station <b>20</b> may suspend application of a load threshold that it would have otherwise applied to wireless link WL<b>4</b> during the handover. As a result, wireless link WL<b>4</b> may temporarily become highly loaded (e.g., the loading on wireless link WL<b>4</b> may temporarily exceed a load threshold).

p-0047At step <b>48</b>, after initiating the handover the communication with mobile station <b>14</b><i>a </i>from wireless link WL<b>1</b> to wireless link WL<b>4</b> (e.g., either during or after the handover), base station <b>20</b> may determine that wireless link WL<b>4</b> is (or will be) highly loaded. In this respect, base station <b>20</b> may determine that wireless link WL<b>4</b> is highly loaded as a result of reinstating application of a load threshold for wireless link WL<b>4</b> that it suspended when initiating the handover of the communication with mobile station from the wireless link WL<b>1</b> to wireless link WL<b>4</b>.

p-0048At step <b>50</b>, in response to determining that wireless link WL<b>4</b> is (or will be) highly loaded, base station <b>20</b> may decide to initiate a handover of a communication from wireless link WL<b>4</b> to another wireless link (e.g., wireless link WL<b>1</b>). In turn, at step <b>52</b>, base station <b>20</b> may identify for the handover a mobile station that is (a) engaging in communication with base station <b>20</b> over wireless link WL<b>4</b> and (b) located outside the coverage area of narrowband repeater <b>28</b> (and thus a communication that is likely occurring directly with base station <b>20</b>). In this respect, base station <b>20</b> will preferably determine whether mobile station <b>14</b><i>b </i>is located outside the coverage area of narrowband repeater <b>28</b> using techniques described above with reference to <figref idrefs="DRAWINGS">FIG. 2</figref>. For example, base station <b>20</b> may use indications of channel quality for the wireless links WL<b>1</b> and WL<b>4</b> that base station <b>20</b> received from mobile station <b>14</b><i>b </i>(e.g., in a handover request and/or a scan report) to determine that mobile station <b>14</b><i>b </i>is located outside the coverage area of narrowband repeater <b>28</b>. Base station <b>20</b> may identify mobile station <b>14</b><i>b </i>using other techniques as well. At step <b>54</b>, base station <b>20</b> may then hand over the communication with mobile station <b>14</b><i>b </i>from wireless link WL<b>4</b> to another wireless link (e.g., wireless link WL<b>1</b>).

p-0049<figref idrefs="DRAWINGS">FIG. 5</figref> is a simplified block diagram showing functional components of an exemplary base station <b>20</b> capable of carrying out the exemplary methods of <figref idrefs="DRAWINGS">FIGS. 2-3</figref>. As shown in <figref idrefs="DRAWINGS">FIG. 5</figref>, exemplary base station <b>20</b> may include an antenna structure <b>102</b>, a communication interface <b>104</b>, a processor <b>106</b>, and data storage <b>108</b>, all linked together via a system bus, network, or other connection mechanism <b>110</b>.

p-0050Referring to <figref idrefs="DRAWINGS">FIG. 5</figref>, the antenna structure <b>102</b> may be the component of exemplary base station <b>20</b> that radiates to define one or more wireless coverage areas and provide one or more wireless links within each wireless coverage area. For purposes of illustration, the following description will assume that the antenna structure <b>102</b> is configured to provide wireless links WL<b>1</b> and WL<b>4</b> in sector S<b>1</b>, wireless links WL<b>3</b> and WL<b>4</b> in sector S<b>2</b>, wireless link WL<b>5</b> in sector S<b>5</b>. The antenna structure <b>102</b> may include one or more antennas arranged in various ways. For example, the one or more antennas may include one or more directional (e.g., sectored) antennas. In another example, the one or more antennas may include one or more antennas for receiving RF signals and one or more antennas for transmitting RF signals. Other configurations are also possible.

p-0051The communication interface <b>104</b> preferably functions to communicatively couple exemplary base station <b>20</b> to other network entities, such as ASN-GW <b>24</b> (and perhaps other entities). As such, the communication interface <b>104</b> may take the form of an Ethernet network interface card, a chipset and antenna adapted to facilitate wireless communication according a desired protocol, and/or any other form that provides for wired and/or wireless communication with ASN-GW <b>24</b>. The communication interface <b>104</b> may also include multiple communication interfaces, such as one through which exemplary base station <b>20</b> sends data to ASN-GW <b>24</b> and one through which exemplary base station <b>20</b> receives data from ASN-GW <b>24</b>. Other configurations are also possible.

p-0052The processor <b>106</b> may comprise one or more general purpose microprocessors and/or dedicated signal processors. (The term “processor” encompasses either a single processor or multiple processors that could work in combination.) Data storage <b>108</b>, in turn, may comprise memory and/or other storage components, such as optical, magnetic, organic or other memory, which can be volatile and/or non-volatile, internal and/or external, and integrated in whole or in part with the processor <b>106</b>. Data storage <b>108</b> preferably contains or is arranged to contain (i) program data <b>112</b> and (ii) program logic <b>114</b>. Although these components are described herein as separate data storage elements, the elements could just as well be physically integrated together or distributed in various other ways. In a preferred example, the program data <b>112</b> would be maintained in data storage <b>108</b> separate from the program logic <b>114</b>, for easy updating and reference by the program logic <b>114</b>.

p-0053Program data <b>112</b> may contain information relating to the wireless links of exemplary base station <b>20</b>. For example, program data <b>112</b> may contain an identifier each wireless link provided by exemplary base station <b>20</b>. As another example, program data <b>112</b> may contain an identifier of a coverage area served by each wireless link provided by exemplary base station <b>20</b>. As yet another example, program data <b>112</b> may contain an indication of whether each wireless link is repeated by a repeater. Other examples are possible as well.

p-0054Program data <b>112</b> may also contain information relating to the mobile stations <b>14</b> engaging in communication with exemplary base station <b>20</b>. For example, program data <b>112</b> may contain an identifier of each mobile station engaging in communication with exemplary base station <b>20</b>. As another example, for each mobile station engaging in communication with exemplary base station <b>20</b>, program data <b>112</b> may contain an identifier for each of the wireless link over which mobile station is currently communicating and one or more other wireless links detected by mobile station <b>14</b>. As yet another example, for each mobile station engaging in communication with exemplary base station <b>20</b>, program data <b>112</b> may contain an indication of channel quality (e.g., CINR and/or RSSI) for each of the wireless link over which mobile station is currently communicating and one or more other wireless links detected by mobile station <b>14</b>. Program data <b>112</b> may contain other types of data as well.

p-0055Program logic <b>114</b> preferably comprises machine-language instructions that may be executed or interpreted by processor <b>106</b> to carry out functions in accordance with the exemplary methods described in <figref idrefs="DRAWINGS">FIGS. 2-3</figref>. It should be understood, however, that the program logic <b>114</b> and its associated functions are described herein by way of example only. As such, those skilled in the art will appreciate that other program logic and/or functions may be used instead, some program logic and/or functions may be added, and some program logic and/or functions may be omitted altogether. Further, the various functions described herein can be embodied in software, hardware, and/or firmware.

p-0056In one aspect, the program logic <b>114</b> may be executable by the processor <b>106</b> to determine whether a mobile station is located inside a coverage area of a repeater. For example, the program logic <b>114</b> may be executable by the processor <b>106</b> to (a) communicate with a mobile station over a first wireless link, (b) receive from the mobile station an indication of channel quality (e.g., CINR and/or RSSI) for each of the first wireless link and a second wireless link detected by mobile station <b>14</b>, (c) determine that the first wireless link and the second wireless link serve a same coverage area of base station <b>20</b>, and (d) after determining that the first wireless link and the second wireless link serve the same coverage area, using the received indications of channel quality for the first wireless link and the second wireless link to determine whether the mobile station is located inside a coverage area of a repeater.

p-0057In another aspect, the program logic <b>114</b> may be executable by the processor <b>106</b> to hand over a communication with a first mobile station moving into a coverage area of a repeater. For example, the program logic <b>114</b> may be executable by the processor <b>106</b> to (a) engage in a communication with the first mobile station over a first wireless link, (b) receive from first mobile station a request to initiate a handover of the communication from the first wireless link to a new wireless link, where the request includes an indication of channel quality for each of the first wireless link and a second wireless link detected by the first mobile station, (c) in response to receiving the request, determine that the first mobile station is moving into a coverage area of a repeater that repeats the second wireless link, and (d) in response to determining that the first mobile station is moving into a coverage area of a repeater that repeats the second wireless link, hand over the communication with the first mobile station from the first wireless link to the second wireless link.

p-0058Additionally, after handing over the communication with the first mobile station from the first wireless link to the second wireless link, the program logic <b>114</b> may be executable by the processor <b>106</b> to (e) determine that the second wireless link is highly loaded, (f) in response to determining that the second wireless link is highly loaded, decide to initiate a handover of a communication from the second wireless link to another wireless link, (g) identify for the handover a second mobile station that is (1) engaging in a communication with the access network over the second wireless link and (2) located outside the coverage area of the repeater, and (h) hand over the communication with the second mobile station from the second wireless link to another wireless link.

p-0059Exemplary embodiments have been described above. Those skilled in the art will understand, however, that changes and modifications may be made to the embodiments described without departing from the true scope and spirit of the present invention, which is defined by the claims.